PUR reactive polyurethane hot melt adhesives are a class of adhesives with better performance in the field of furniture edge banding. Its unique moisture curing mechanism gives it many characteristics that distinguish it from traditional EVA hot melt adhesives.The main component of PUR hot melt adhesive is a terminal isocyanate-based (-NCO) polyurethane prepomer, which has fluidity similar to hot melt adhesive in the heated and molten state, and can be coated on the slotted surface of the sheet for edge banding operation.Unlike EVA hot melt adhesives, which rely purely on physical cooling for curing, PUR adhesives are cooled and initially shaped. The active isocyanate group in their molecular structure will react chemically with trace amounts of moisture in the environment to generate urea groups and further cross-link to form a three-dimensional mesh structure.This reaction process usually takes several hours to 24 hours to complete, so that the adhesive layer changes from thermoplastic to thermosetting.

The curing mechanism of PUR hot melt adhesive determines that it has excellent overall performance after it is completely cured.The mesh structure formed by the crosslinking gives the adhesive layer higher cohesion strength and better heat resistance. The cured PUR adhesive layer will not soften and flow like EVA in a high temperature environment, and can withstand higher operating temperatures.Chemical crosslinking also significantly improves the water, moisture and chemical resistance of the adhesive layer. Even if it is in a humid environment for a long time or in contact with cleaning agents, the bonding strength can still remain stable.For furniture products that need to withstand temperature changes and humidity tests, such as kitchen cabinets, bathroom cabinets, etc., the durability advantages of PUR edge banding glue are particularly prominent.

At the level of edge banding process, the moisture-curing characteristics of PUR hot melt adhesives require special measures to be taken during use.When the glue is in contact with the air in the heated state, it will gradually absorb moisture and react in advance. Therefore, the PUR glue tank and the glue coating system need to be sealed to reduce the contact surface between the glue and the air.The PUR glue after opening should be used as soon as possible to avoid long-term exposure that causes the viscosity to increase or gel.The product after edge banding should avoid contact with moisture and excessive external force before the crosslinking reaction is completed.Although the process requirements are more stringent than EVA, the excellent performance provided by PUR hot melt adhesive in high-end furniture edge banding makes it the material of choice for application scenarios with high requirements for durability and environmental adaptability.